No matter how simple or straightforward a task seems, there is a correct and incorrect way to do it. This tub was re caulked at some point using a product not suitable for damp locations, we are removing it as part of a 5-figure mold and mildew remediation project.
Jonathan Cheville thank you for posting this The same was done in our shower by the old home owners and just like the photo, it was always moldy until we had it fixed!